在UIKit中获取内存泄漏？

Question

当我在仪器中测试我的应用程序内存泄漏时，我什么也没找到（使用模拟器运行）。但是当我在移动设备中运行它然后检查时，UIKit对象中有很多泄漏。这种情况发生在每个视图中。在模拟器中没有出现这样的泄漏。

下面是仪器的屏幕截图，其中发生了一些泄漏。

当我从HomeView移动到secondViewController时，没有发现泄漏。如果再次回到家中，会发现这些泄漏。所以，这是否意味着，我必须释放/ nil我在第二个View中使用的所有UI对象。以下是我在secondView中使用的UI对象。

1.Two Background UIImageView
2.One TitleBar UIImageView
3.3 UIButtons(Back,left and right button for iCarousel)
4.One iCarousel view
5.UIPageController(For this I have used a third Party code SMPageControl)
6.One title label. 

注意：我的是非ARC代码。

之前有没有人遇到过这个问题。我怎么能克服这个问题，因为我的App中的每个View都有这个问题。因为这个问题，我的应用程序频繁出现内存并经常崩溃。

谢谢。

以下是该视图的实现文件。

EDIT1：

 @implementation CatalogueViewController

@synthesize deptCarousel    = _deptCarousel;
@synthesize carouselItems   = _carouselItems;
@synthesize categorymAr     = _categorymAr;
@synthesize spacePageControl = _spacePageControl;
@synthesize wrap;

- (void)dealloc {
    _deptCarousel = nil;
    [_categorymAr               release];
    _categorymAr                = nil;
    _deptCarousel.delegate      = nil;
    _deptCarousel.dataSource    = nil;
    [_deptCarousel              release];
    [_carouselItems             release];
    [viewGesture release];
    viewGesture = nil;
    [_spacePageControl release];
    _spacePageControl = nil;
    imgViewBG = nil;
    imgViewBG2 = nil;
    btnPrev = nil;
    btnNext = nil;
//    [self releaseObjects];
    [super dealloc];
}


- ( IBAction) btnBackClicked {
    [self.navigationController popViewControllerAnimated:YES];
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.title = NSLocalizedString(@"catalogue", @"Catalogue");

    // Do any additional setup after loading the view from its nib.

    _deptCarousel.type  = iCarouselTypeLinear;
    _deptCarousel.scrollSpeed = 0.3f;
    _deptCarousel.bounceDistance = 0.1f;
    _deptCarousel.scrollToItemBoundary = YES;
    _deptCarousel.stopAtItemBoundary = YES;
    [_deptCarousel setScrollEnabled:NO];

    UISwipeGestureRecognizer *swipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeNext:)];
    swipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
    [viewGesture addGestureRecognizer:swipeLeft];
    [swipeLeft release];

    UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipePrev:)];
    swipeRight.direction = UISwipeGestureRecognizerDirectionRight;
    [viewGesture addGestureRecognizer:swipeRight];
    [swipeRight release];

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
    [viewGesture addGestureRecognizer:singleTap];
    [singleTap release];

    _carouselItems      = [[NSMutableArray alloc] initWithCapacity:1];
    _categorymAr        = [[NSMutableArray alloc] initWithCapacity:1];
    [self addCatalogues];
    _spacePageControl.numberOfPages = [_categorymAr count];
    [_spacePageControl setPageIndicatorImage:[UIImage imageNamed:IS_IPAD?@"Marker1.fw.png" : @"Markeri.png"]];
    [_spacePageControl setCurrentPageIndicatorImage:[UIImage imageNamed:IS_IPAD?@"Marker-Highlight.png" : @"Marker-Highlight_i.png"]];
    [_spacePageControl addTarget:self action:@selector(spacePageControl:) forControlEvents:UIControlEventValueChanged];

}



- (void)spacePageControl:(SMPageControl *)sender{
    [_deptCarousel scrollToItemAtIndex:sender.currentPage animated:YES];
}

- ( void ) addCatalogues {
    [_categorymAr addObjectsFromArray:[[DBModel database] categoryList]];

    for (int i = 0; i < [_categorymAr count]; i++) {
        [_carouselItems addObject:[NSNumber numberWithInt:i]];
    }
    [_deptCarousel reloadData];
}

- (void)viewDidUnload{

    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)viewWillAppear:(BOOL)animated
{
    [self phoneType];
    [super viewWillAppear:animated];
    if (IS_IPAD) {
        UIInterfaceOrientation statusBarOrientation = [[UIApplication sharedApplication] statusBarOrientation];
        [self handleOrientation:statusBarOrientation];
    }
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
 }


- ( void ) phoneType{

    if(!IS_IPAD){
        if(IS_IPHONE5){
            imgViewBG.image = [UIImage imageNamed:@"Background5_5.jpg"];
            imgViewBG.center = CGPointMake(162,265);
            imgViewBG2.image = [UIImage imageNamed:@"Background11_5.png"];
            _spacePageControl.center = CGPointMake(160, 478);
            _deptCarousel.center = CGPointMake(160, 355);
            viewGesture.center = CGPointMake(160, 355);
            btnPrev.center = CGPointMake(25, 355);
            btnNext.center = CGPointMake(295, 355);
        }
        else{
            imgViewBG.image = [UIImage imageNamed:@"Background5.jpg"];
            imgViewBG2.image = [UIImage imageNamed:@"Background9.png"];            
        }
    }

}


-(void)textFieldDidBeginEditing:(UITextField *)textField{

    textFieldSearch.placeholder = @"";
    UIButton *clearButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];
    [clearButton setImage:[UIImage imageNamed:IS_IPAD?@"Btn_X_Large.fw.png":@"Btn_X.fw.png"] forState:UIControlStateNormal];
    [clearButton addTarget:self action:@selector(btnClearTextField) forControlEvents:UIControlEventTouchUpInside];
    [textFieldSearch setRightViewMode:UITextFieldViewModeAlways];
    [textFieldSearch setRightView:clearButton];
    [clearButton release];

}

-(void)textFieldDidEndEditing:(UITextField *)textField{
    [textFieldSearch setRightView:nil];
    if ([textFieldSearch.text isEqualToString:@""]) {
        textFieldSearch.placeholder = NSLocalizedString(@"hud_search_for_a_product_here",@"");
    }
}

-(IBAction)btnClearTextField{
    textFieldSearch.text = @"";
}

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskAll;
}



- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    if (IS_IPAD) {
        return YES;
    } else {
        return (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown);
    }
}

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation )toInterfaceOrientation duration:(NSTimeInterval)duration{
    if (IS_IPAD) {
        [self handleOrientation:toInterfaceOrientation];
    }
}

- ( void ) handleOrientation:(UIInterfaceOrientation )toInterfaceOrientation {



    if (toInterfaceOrientation == UIInterfaceOrientationPortrait || toInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
        imgViewBG.image = [UIImage imageNamed:@"Background_Catalogue_P.jpg"];
        imgViewBG2.image = [UIImage imageNamed:@"Background_Overlay_P.fw.png"];
        btnPrev.center = CGPointMake(90, 640);
        btnNext.center = CGPointMake(677, 640);
        textFieldSearch.frame = CGRectMake(187, 54, 418, 25);
        _deptCarousel.frame = CGRectMake(235, 250, 300, 800);
        _spacePageControl.center = CGPointMake(385, 920);
        viewGesture.center = CGPointMake(385, 658);

    }else {
        imgViewBG.image = [UIImage imageNamed:@"Background_Catalogue_L.jpg"];
        imgViewBG2.image = [UIImage imageNamed:@"Background_Overlay_L.fw.png"];
        btnPrev.center = CGPointMake(54, 385);
        btnNext.center = CGPointMake(640, 385);
        textFieldSearch.frame = CGRectMake(240, 55, 567, 25);
        _deptCarousel.frame = CGRectMake(50, 250, 600, 300);
        _spacePageControl.center = CGPointMake(346, 660);
        viewGesture.center = CGPointMake(347, 405);

    }
}

- ( IBAction )btnDepartmentClicked:(id)sender {
    int btnTag = [sender tag];
    ProductCategoriesViewController *productView = [[ProductCategoriesViewController alloc] initWithNibName:@"ProductCategoriesView" bundle:nil];
    if ( btnTag == 0 ) {
        [productView setStrTitle:NSLocalizedString(@"women", @"Women")];
    }else if ( btnTag == 1 ) {
        [productView setStrTitle:NSLocalizedString(@"men", @"Men")];
    } else {
        [productView setStrTitle:NSLocalizedString(@"sports", @"Sports")];
    }
    [self.navigationController pushViewController:productView animated:YES];

    [productView release];
}


- ( BOOL ) textFieldShouldReturn:( UITextField * )textField {
    [textField resignFirstResponder];
    [Flurry logEvent:@"Product searched" withParameters:[NSDictionary dictionaryWithObjectsAndKeys:textField.text,@"1", nil]];
    [self productSearch:textField.text isBar:NO isQR:NO];
    return YES;
}

- ( void ) productSearch:( NSString * )_searchText isBar:( BOOL )_isBar isQR:( BOOL )_isQr {
    if ([_searchText isEqualToString:@""]) {
        return;
    }

    NSMutableArray *ProductList = [[NSMutableArray alloc] init];
    [ProductList addObjectsFromArray:[[DBModel database] productSearch:_searchText isBar:_isBar isQR:_isQr]];
    if ( [ProductList count] == 0 ) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"product", @"")
                                                        message:NSLocalizedString(@"cannot_find_product", @"")
                                                       delegate:nil
                                              cancelButtonTitle:NSLocalizedString(@"ok", @"")
                                              otherButtonTitles:nil];
        [alert show];
        [alert release];        
    } else {
        GeneralProductListViewController *generalProductList = [[GeneralProductListViewController alloc] initWithNibName:IS_IPAD?@"GeneralProductListView~iPad": @"GeneralProductListView" bundle:nil];
        [generalProductList setMArProducts:ProductList];
        [self.navigationController pushViewController:generalProductList animated:YES];
        [generalProductList release];
    }
    [ProductList release];
  }


-(IBAction) spin:(id)sender {


    if([sender tag]==0)
    {

        [_deptCarousel scrollToItemAtIndex:[self.deptCarousel currentItemIndex]+1 animated:YES];
//         [_deptCarousel scrollByNumberOfItems:1 duration:2.0];
        }

    else{
     [_deptCarousel scrollToItemAtIndex:[self.deptCarousel currentItemIndex]-1 animated:YES];

    }

}

-(void)swipeNext:(UISwipeGestureRecognizer *)recognizer{

     [_deptCarousel scrollToItemAtIndex:[self.deptCarousel currentItemIndex]+1 animated:YES];

}

-(void)swipePrev:(UISwipeGestureRecognizer *)recognizer{

    [_deptCarousel scrollToItemAtIndex:[self.deptCarousel currentItemIndex]-1 animated:YES];

}

-(void) handleSingleTap:(UITapGestureRecognizer *)recognizer{

    if ([_categorymAr count] > 0) {

        ProductCategoriesViewController *prodCatView = [[ProductCategoriesViewController alloc] initWithNibName:IS_IPAD ?
                                                    @"ProductCategoriesView~iPad" : @"ProductCategoriesView" bundle:nil];
        Category *categoryObj = [_categorymAr objectAtIndex:[self.deptCarousel currentItemIndex]];
        [prodCatView setStrTitle:categoryObj.categoryName];
        [prodCatView setCategoryId:categoryObj.categoryId];
        [Flurry logEvent:@"Category List" withParameters:[NSDictionary dictionaryWithObjectsAndKeys:categoryObj.categoryName,[NSString stringWithFormat:@"%d",categoryObj.categoryId], nil]];
        [self.navigationController pushViewController:prodCatView animated:YES];
        [prodCatView release];
    }
}
//-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
//    pageControl.currentPage = [self.deptCarousel currentItemIndex] ;
//}

#pragma mark
#pragma mark NavigationBarViewDelegate metho

- ( void ) navigationBackClicked {
    [self.navigationController popViewControllerAnimated:YES];
}

#pragma mark -
#pragma mark iCarousel methods

- (NSUInteger)numberOfItemsInCarousel:(iCarousel *)carousel
{
    return [_carouselItems count];
}

- (NSUInteger)numberOfVisibleItemsInCarousel:(iCarousel *)carousel
{
    //limit the number of items views loaded concurrently (for performance reasons)
    return NUMBER_OF_VISIBLE_ITEMS;
}

- (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index
{
    Category *categoryObj = [_categorymAr objectAtIndex:index];
    //create a numbered view
    UIView *view = nil;
    NSString *imagePath = [[APP_CACHES_DIR stringByAppendingPathComponent:@"catalogues"] stringByAppendingString:[NSString stringWithFormat:@"/%d.jpg", categoryObj.categoryId]];
    if (![[NSFileManager defaultManager] fileExistsAtPath:imagePath]) {
        view = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:IS_IPAD?@"Gallery Placeholder.png":@"Gallery Placeholder.png"]] autorelease];
    } else {
        view = [[[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile:[[APP_CACHES_DIR stringByAppendingPathComponent:@"catalogues"] stringByAppendingString:[NSString stringWithFormat:@"/%d.jpg", categoryObj.categoryId]]]] autorelease];
    }



    if (IS_IPAD) {
        view.frame = CGRectMake(0, 0, 420, 420);
    } else {
        view.frame = CGRectMake(0, 0, 200, 200);
    }

//  UILabel *label = [[[UILabel alloc] initWithFrame:CGRectMake(view.bounds.origin.x, view.bounds.origin.y+view.bounds.size.height, view.bounds.size.width, 44)] autorelease];
//  label.text = categoryObj.categoryName;
//    label.textColor = [UIColor blackColor];
//  label.backgroundColor = [UIColor clearColor];
//  label.textAlignment = UITextAlignmentCenter;
//    label.font = [UIFont fontWithName:@"Helvetica-Bold" size:IS_IPAD?26:14];
//  [view addSubview:label];


    return view;
}

- (NSUInteger)numberOfPlaceholdersInCarousel:(iCarousel *)carousel
{
    //note: placeholder views are only displayed on some carousels if wrapping is disabled
    return INCLUDE_PLACEHOLDERS? 2: 0;
}

- (UIView *)carousel:(iCarousel *)carousel placeholderViewAtIndex:(NSUInteger)index
{
    //create a placeholder view
    UIView *view = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:@""]] autorelease];
    UILabel *label = [[[UILabel alloc] initWithFrame:view.bounds] autorelease];
    label.text = (index == 0)? @"[": @"]";
    label.backgroundColor = [UIColor clearColor];
    label.textAlignment = UITextAlignmentCenter;
    label.font = [label.font fontWithSize:50];

    _spacePageControl.currentPage = index;


//  [view addSubview:label];
    return view;
}

- (CGFloat)carouselItemWidth:(iCarousel *)carousel
{
    //usually this should be slightly wider than the item views
    return ITEM_SPACING;
}

- (CATransform3D)carousel:(iCarousel *)_carousel transformForItemView:(UIView *)view withOffset:(CGFloat)offset
{
    //implement 'flip3D' style carousel

    //set opacity based on distance from camera
    view.alpha = 1.0 - fminf(fmaxf(offset, 0.0), 1.0);

    //do 3d transform
    CATransform3D transform = CATransform3DIdentity;
    transform.m34 = _deptCarousel.perspective;
    transform = CATransform3DRotate(transform, M_PI / 8.0, 0, 1.0, 0);

    return CATransform3DTranslate(transform, 0.0, 0.0, offset * _deptCarousel.itemWidth);
}

- (BOOL)carouselShouldWrap:(iCarousel *)carousel
{
    //wrap all carousels
//    return NO;
    return wrap;
}

- (void)carousel:(iCarousel *)carousel didSelectItemAtIndex:(NSInteger)index {
    if (index == [self.deptCarousel currentItemIndex]) {
        ProductCategoriesViewController *prodCatView = [[ProductCategoriesViewController alloc] initWithNibName:IS_IPAD ? 
                                                        @"ProductCategoriesView~iPad" : @"ProductCategoriesView" bundle:nil];
        Category *categoryObj = [_categorymAr objectAtIndex:index];
        [prodCatView setStrTitle:categoryObj.categoryName];
        [prodCatView setCategoryId:categoryObj.categoryId];
        [Flurry logEvent:@"Category List" withParameters:[NSDictionary dictionaryWithObjectsAndKeys:categoryObj.categoryName,[NSString stringWithFormat:@"%d",categoryObj.categoryId], nil]];
        [self.navigationController pushViewController:prodCatView animated:YES];
        [prodCatView release];
    }
}

-(void) carouselDidScroll:(iCarousel *)carousel{

//    [_deptCarousel scrollToItemAtIndex:[self.deptCarousel currentItemIndex]+3 animated:YES];

//    [_deptCarousel scrollByNumberOfItems:1 duration:1];

}

- (void)carouselCurrentItemIndexUpdated:(iCarousel *)carousel{

    _spacePageControl.currentPage = [self.deptCarousel currentItemIndex];
}

- ( IBAction ) myCart {
    if ( [[DBModel database] isShoppingListEmpty] ) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"at_shopping_cart", @"") 
                                                        message:NSLocalizedString(@"amsg_shopping_cart_empty", @"")
                                                       delegate:nil cancelButtonTitle:NSLocalizedString(@"ok", @"") otherButtonTitles:nil];
        [alert show];
        [alert release];
        return;
    }
    MyCartViewController *myCartView = [[MyCartViewController alloc] initWithNibName:IS_IPAD ? @"MyCartView~iPad" : @"MyCartView" bundle:nil];
    [self.navigationController pushViewController:myCartView animated:YES];
    [myCartView release];
}

Answer 1

首先，如前所述，使用ARC。没有任何一件事可以做到更能改善内存管理。

无论您是否使用ARC，都应始终使用访问者来访问您的ivars（init和dealloc除外）。正如@LombaX所述，您在viewDidLoad中错误地设置了您的ivars。使用访问器会有所帮助。

您应该运行静态分析器，这将帮助您找到其他内存错误。

我怀疑您的IBOutlet配置为retain并且您未在dealloc中发布。这是我在截图中看到的泄漏的最可能原因。 ARC通常会自动消除这些问题。

你很可能有一个保留循环。这通常不会显示为泄漏。您应该使用heapshot进行调查。你的泄漏很小;它们可能不是记忆警告的实际原因。您想要研究的内容（使用Allocations仪器）实际上是在显着增加您的内存使用量。

但首先是ARC。然后访问者。然后删除所有构建警告。然后删除所有静态分析器警告。然后使用分配工具。

旁注：事实上它说责任方是“UIKit”并不意味着这是UIKit中的一个错误。这只意味着UIKit分配了后来泄露的内存。泄漏的原因可能在其他地方。 （那说，UIKit确实有几个小泄漏。一般来说，它们不应该给你带来麻烦，但你可能永远无法摆脱iOS应用程序中100％的小泄漏。）

Answer 2

首先：

你有可能的，可见的泄漏，但我不确定它是否与仪器中发现的泄漏相同：

这两行是在viewDidLoad方法

中

_carouselItems      = [[NSMutableArray alloc] initWithCapacity:1];
_categorymAr        = [[NSMutableArray alloc] initWithCapacity:1];

但是：每当视图由其控制器加载时，都会调用viewDidLoad:。如果控制器清除视图（例如在内存警告之后），则在第二个viewDidLoad中，您的_carouselItems和_categorymAr实例变量将丢失对先前创建的NSMutableArray的引用，从而导致泄漏

因此，更改那些行并使用syntesized setter：

self.carouselItems      = [[[NSMutableArray alloc] initWithCapacity:1] autorelease];
self.categorymAr        = [[[NSMutableArray alloc] initWithCapacity:1] autorelease];

syntesized setter配置为在分配新对象之前释放先前的对象。

然而：你可能有另一次泄漏。 如果您可以简单地重现泄漏（如果我理解，泄漏只是从VC移动到另一个），您可以使用仪器的“快照”功能。

假设您的泄漏从第一个VC移动到第二个VC并且返回：

• 使用分配工具打开工具
• 从第一个VC转到第二个VC然后回来。
• 按左侧的“标记堆”。将出现一条线。
• 从第一个VC再到第二个VC然后回来。
• 再次按“快照”
• 这样做几次（9-10）

快照工具会在您按下按钮时获取生物对象的“快照”，并仅显示差异。 如果有2-3个新对象，您将在列表中看到它。

这是调查泄漏的良好起点。 看附图：

考虑到您必须多次标记堆并通过查看创建的对象来区分“误报”，在我的示例中，您可以查看可能的泄漏（heapshot5,166KB），但在查看内容后，它不是 - ＆GT;这是一个在那一刻开始的后台任务。

此外，自动释放池的延迟和一些UIKit对象的缓存可以在快照中显示一些内容，这就是为什么我说尝试几次。

Answer 3

检测泄漏源的一种简单方法是使用仪器的扩展详细信息视图。

要执行此操作，请单击“查看” - ＆gt;“扩展详细信息”，并显示带有“泄漏”堆栈跟踪的右侧菜单。在那里，您可以轻松找到每个泄漏的泄漏代码，以及它们是否来自您的应用程序。